John L. Melanson, Austin US

John L. Melanson, Austin, TX US

Patent application number

Description

Published

20080224629

LIGHTING SYSTEM WITH POWER FACTOR CORRECTION CONTROL DATA DETERMINED FROM A PHASE MODULATED SIGNAL - A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used bit the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal.

09-18-2008

20080224631

Color variations in a dimmable lighting device with stable color temperature light sources - A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source.

09-18-2008

20080224633

Lighting System with Lighting Dimmer Output Mapping - A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level.

09-18-2008

20080224636

POWER CONTROL SYSTEM FOR CURRENT REGULATED LIGHT SOURCES - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

09-18-2008

20080272744

POWER CONTROL SYSTEM USING A NONLINEAR DELTA-SIGMA MODULATOR WITH NONLINEAR POWER CONVERSION PROCESS MODELING - A power control system includes a switching power converter and a power factor correction (PFC) and output voltage controller. The switching power converter utilizes a nonlinear energy transfer process to provide power to a load. The PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. The PFC and output voltage controller includes a nonlinear delta-sigma modulator that models the nonlinear energy transfer process of the switching power converter. The nonlinear delta-sigma modulator generates an output signal used to determine the control signal. By using the nonlinear delta-sigma modulator in a control signal generation process, the PFC and output voltage controller generates a spectrally noise shaped control signal. In at least one embodiment, noise shaping of the control signal improves power factor correction and output voltage regulation relative to conventional systems.

11-06-2008

20080272745

POWER FACTOR CORRECTION CONTROLLER WITH FEEDBACK REDUCTION - A power control system includes a feedback loop having a power factor correction (PFC) and output voltage controller and a switching power converter. The switching power converter includes an inductor to supply charge to an output capacitor and a switch to control inductor current ramp-up times. The PFC and output voltage controller provides a control signal to the switch to control PFC and regulate output voltage of the switching power converter. During a single period of the control signal, the PFC and output voltage controller obtains the line input voltage and output voltage of the switching power converter using a single feedback signal received from the switching power converter.

11-06-2008

20080272746

POWER FACTOR CORRECTION CONTROLLER WITH SWITCH NODE FEEDBACK - A power control system includes a switching power converter and a power factor correction (PFC) and output voltage controller. The PFC and output voltage controller provides a control signal to a switch to control power factor correction and regulate output voltage of the switching power converter. During a single period of the control signal, the PFC and output voltage controller determines the line input voltage, the output voltage, or both using a single feedback signal received from the switching power converter. The feedback signal is received from a switch node located between an inductor and the switch. The PFC and output voltage controller determines either the line input voltage or the output voltage, whichever was not determined from the feedback signal, using a second feedback signal received from either a PFC stage or a driver stage of the switching power converter.

11-06-2008

20080272747

PROGRAMMABLE POWER CONTROL SYSTEM - A power control system includes a switching power converter and a programmable power factor correction (PFC) and output voltage controller. The programmable PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. In at least one embodiment, the control signal is a pulse width modulated signal. The programmability of the PFC and output voltage controller provides the programmable PFC and output voltage controller flexibility to operate in accordance with programmable parameters, to adapt to various operating environments, and to respond to various operating exigencies. In at least one embodiment, the programmable PFC and output voltage controller includes a state machine to process one or more programmable, operational parameters to determine the period and pulse width states of the control signal.

11-06-2008

20080272755

SYSTEM AND METHOD WITH INDUCTOR FLYBACK DETECTION USING SWITCH GATE CHARGE CHARACTERISTIC DETECTION - A method and system monitor gate charge characteristics of one or more field effect transistors in a switching power converter to detect an end of an inductor flyback time interval. The switching power converter includes a switch coupled to an inductor to control current flow in the inductor. When the switch turns OFF, a collapsing magnetic field causes the inductor current to decrease and the inductor voltage to reverse polarity. When the magnetic field completely collapses, the inductor current goes to zero. At the end of the inductor flyback time interval, a voltage is induced across a Miller capacitance of the switch. The voltage can be detected as a transient change in the gate voltage of the switch. A switch gate sensor detects the gate voltage change associated with the end of the inductor flyback time interval and provides a signal indicating an end of the inductor flyback time interval.

11-06-2008

20080272756

POWER FACTOR CORRECTION CONTROLLER WITH DIGITAL FIR FILTER OUTPUT VOLTAGE SAMPLING - A power control system includes a digital FIR filter in an output voltage feedback loop of a switching power converter. A feedback loop includes an output voltage signal of the switching power converter. The output voltage signal includes direct current (DC) and alternating current (AC) components. The FIR filter provides discrete samples of an output voltage feedback signal to a switch state controller that allows the switch state controller to generate a control signal that reflects a relatively quick response to changes in the output voltage signal while reducing an influence of the AC component. In at least one embodiment, the FIR filter is configured to generate the discrete samples at a sampling frequency f

11-06-2008

20080272757

POWER SUPPLY DC VOLTAGE OFFSET DETECTOR - A power supply output voltage direct current (DC) offset detector determines a DC offset in a power supply output voltage signal, and the output voltage signal has a DC component and an alternating current (AC) “ripple” component. Once during each period of the ripple, the DC offset detector determines the DC offset from an output voltage signal using a comparison between the output voltage signal and a reference voltage. In at least one embodiment, from the comparison and during a period of the ripple, the DC offset detector determines an ‘above’ duration for which the ripple is above the reference voltage, determines a ‘below’ duration for which the ripple is below the reference voltage, or both to determine the DC offset of the power supply output voltage signal. The DC offset detector uses the above and/or below duration(s) to determine the DC offset of the output voltage signal.

11-06-2008

20080272758

Switching Power Converter with Switch Control Pulse Width Variability at Low Power Demand Levels - A power control system includes a switch mode controller to control the switching mode of a switching power converter. The switch mode controller generates a switch control signal that controls conductivity of a switch of the switching power converter. Controlling conductivity of the switch controls the switch mode of the switching power converter. The switch mode controller includes a period generator to determine a period of the switch control signal and to vary the determined period to generate a broad frequency spectrum of the switch control signal when the determined period corresponds with a frequency in at least a portion of an audible frequency band. Generating a switch control signal with a broad frequency spectrum in the audible frequency band allows the system to utilize switching frequencies in the audible frequency band.

11-06-2008

20080272945

CONTROL SYSTEM USING A NONLINEAR DELTA-SIGMA MODULATOR WITH NONLINEAR PROCESS MODELING - A control system includes a nonlinear delta-sigma modulator, and the nonlinear delta-sigma modulator includes a nonlinear process model that models a nonlinear process in a signal processing system, such as a nonlinear plant. The nonlinear delta-sigma modulator includes a feedback model that models the nonlinear process being controlled and facilitates spectral shaping to shift noise out of a baseband in a spectral domain of a response signal of the nonlinear process. In at least one embodiment, the nonlinear delta-sigma modulator is part of a control system that controls power factor correction and output voltage of a switching power converter. The control system controls the pulse width and period of a control signal to control power factor correction and the output voltage level. In at least one embodiment, the nonlinear delta-sigma modulator generates a signal to control the pulse width of the control signal.

11-06-2008

20080272946

SIGNAL PROCESSING SYSTEM USING DELTA-SIGMA MODULATION HAVING AN INTERNAL STABILIZER PATH WITH DIRECT OUTPUT-TO-INTEGRATOR CONNECTION - A signal processing system includes an analog-to-digital delta sigma modulator with a duty cycle modulator and a finite impulse response (FIR) filter in a main loop feedback path of the delta sigma modulator. The duty cycle modulator and FIR filter can provide high performance filtering in the main loop feedback path. To prevent instability in the main loop caused by the duty cycle modulator and FIR filter, the delta sigma modulator also includes a stabilizer loop. Transfer functions of the main loop and the stabilizer loop combine to achieve a target transfer function for the analog-to-digital delta sigma modulator that provides for stable operation of the analog-to-digital delta sigma modulator. In at least one embodiment, the stabilizer loop includes a stabilizer path that provides output data directly to an integrator of the main loop filter.

11-06-2008

20080273356

Switching Power Converter with Efficient Switching Control Signal Period Generation - A power control system includes a switching power converter and a controller, and the controller responds to a time-varying voltage source signal by generating a switch control signal having a period that varies in accordance with at least one of the following: (i) the period of the switch control signal trends inversely to estimated power delivered to a load coupled to the switching power converter, (ii) the period of the switch control signal trends inversely to instantaneous voltage levels of the voltage source signal, and (iii) the period of the switch control signal trends directly with a line voltage level of the time-varying voltage source signal. In at least one embodiment, the controller achieves an efficient correlation between the switching period with associated switching losses and the instantaneous power transferred to the switching power converter while providing power factor correction (PFC).

11-06-2008

20080315791

HYBRID GAS DISCHARGE LAMP-LED LIGHTING SYSTEM - A lighting system and method combine at least one LED and at least one gas discharge lamp within a common housing. The lighting system includes a control system to dependently operate each LED and each gas discharge lamp during overlapping, non-identical periods of time. In at least one embodiment, the control system can provide light output by activating LEDs during gas discharge preheating operations and thus extend the useful life of each gas discharge lamp. When dimming the lighting system, the control system can reduce current to the gas discharge lamps and one or more gas discharge lamps can be phased out as dimming levels decrease. As dimming levels decrease, one or more of the LEDs can be activated or groups of LEDs can be phased in to replace the light output of the dimmed gas discharge lamps. Thus, the lighting system can reduce power consumption at low dimming levels.

12-25-2008

20090085625

TIME-BASED CONTROL OF A SYSTEM HAVING INTEGRATION RESPONSE - A time-based controller provides control for a controlled system including a plant having an integration response. The time-based controller includes a comparator that detects a polarity change in a comparison of a sensed signal from the plant and a reference signal while a control signal is in a first state, time calculation logic that, responsive to detection of the change in the comparison, determines a time at which to change a state of a control signal supplied to the plant, and a modulator that, at the determined time, changes the state of the control signal supplied to the plant from the first state to a second state.

04-02-2009

20090085657

COMPENSATION OF FIELD EFFECT ON POLYCRYSTALLINE RESISTORS - A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.

04-02-2009

20090147544

MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A modulated transformer-coupled gate control signaling method and apparatus provides reduction of circuit complexity and robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Power for the demodulator can be obtained by rectifying the modulated control signal at the demodulator, or from another transformer winding. The modulation scheme is chosen to have a DC average value of zero, eliminating any magnetization current management requirements. The modulated control signal may carry redundant control information and/or may encode additional information to provide a more sophisticated gate drive control, such as oversampled gate control information.

06-11-2009

20090147545

HISTORY-INDEPENDENT NOISE-IMMUNE MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A history-independent and noise-immune modulated transformer-coupled gate control signaling method and apparatus provides robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Codes specified by relative timing of transitions in multiple periods of the modulated control are assigned to gate-on and gate-off timing events that control the switching transistor gate(s) and unassigned patterns are decoded as gate-off events, reducing the possibility that a switching transistor will be erroneously activated due to noise. The modulated signal is constructed so that signal history is not required for decoding, eliminating any requirement of a reference clock. Blanking may be employed to conserve power between codes and to avoid mis-triggering due to noise events during power switching.

06-11-2009

20090189579

SWITCH STATE CONTROLLER WITH A SENSE CURRENT GENERATED OPERATING VOLTAGE - A power supply system and method includes a switch state controller that is operational to control a switching power converter during certain power loss conditions that cause conventional switch state controllers to have diminished or no functionality. In at least one embodiment, during certain power loss conditions, such as when an auxiliary power supply is in standby mode or when the switching power converter is not operating, a power supply for the switch state controller does not provide sufficient operating power to the switch state controller during certain power loss conditions. In at least one embodiment, during such power loss conditions power is generated for the switch state controller using sense input and/or sense output currents of the switching power converter to allow an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the switching power converter.

07-30-2009

20090190379

SWITCHING REGULATOR WITH BOOSTED AUXILIARY WINDING SUPPLY - A boosted auxiliary winding power supply for a switched-power converter circuit provides operating voltage for control and other circuits early in the start-up phase of converter operation. A boost circuit has an input coupled to the auxiliary winding to boost the voltage available from the auxiliary winding at least during start-up of the switched-power converter. The boost thereby provides a voltage that is greater than the voltage across the auxiliary winding during start-up of the switched-power converter. The boost circuit may be actively switched at a rate higher than a switching rate of the switched-power converter, to increase a rate of rise of the operating voltage. Polarity information, which may be provided from the switched-power converter control circuit, can be used to actively rectify the output of the auxiliary winding.

07-30-2009

20090190384

POWERING A POWER SUPPLY INTEGRATED CIRCUIT WITH SENSE CURRENT - A power control system and method senses input and/or output voltages of a power supply using sense currents in order for an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the power control system. By sensing sense currents, the power control system can eliminate at least one sense resistor used in a voltage sense system. The sense current(s) can be used to provide power and sensing to the switch state controller. In at least one embodiment, the sense current(s) provide power to the switch state controller when auxiliary IC power is unavailable or diminished, such as during start-up of the IC. In at least one embodiment, the IC draws more sense current from an input of the power control system than the output of the power control system to, for example, minimize impact on the output voltage of the power supply.

07-30-2009

20090191837

Delta Sigma Modulator with Unavailable Output Values - A power control system includes a delta sigma modulator to generate output values for use in controlling a switching power converter. In at least one embodiment, the delta sigma modulator includes two ranges of available output values and a range of one or more unavailable intermediate output values, wherein the range of one or more unavailable intermediate output values represent a gap in available output values. Each unavailable intermediate output value represents an output value that is not generated by the delta sigma modulator. In at least one embodiment, the delta sigma modulator includes a quantizer output remapping module that remaps quantizer output values within the range of one or more unavailable intermediate output values of the delta sigma modulator to new output values within one of the ranges of available output values.

07-30-2009

20090212759

TRANSFORMER-ISOLATED ANALOG-TO-DIGITAL CONVERTER (ADC) FEEDBACK APPARATUS AND METHOD - A transformer-isolated analog-to-digital converter (ADC) feedback apparatus and method provides reduction of circuit complexity in high power/high voltage systems having a transformer-isolated sensing circuit. The feedback apparatus is a circuit including an ADC for receiving an analog input signal and a transformer having a first winding that receives a modulated output of the analog-to-digital converter. A second winding of the transformer provides an isolated data output of the ADC. A demodulator is coupled to the second winding of the transformer and demodulates the isolated output to generate a digital representation of the analog input signal. The ADC may be a delta-sigma converter and the demodulator may be the corresponding decimation filter. The circuit further includes an isolation circuit for introducing a clock signal and/or power supply waveform at the second winding of the transformer, so that the ADC circuit is supplied with an isolated clock and/or an isolated power supply.

08-27-2009

20090243591

POWER METER HAVING COMPLEX QUADRATURE OUTPUT CURRENT AND VOLTAGE FILTERS - A power meter having complex quadrature output current and voltage filters provides power measurements in high amplitude and frequency variation and/or high jitter environments without requiring high computational overhead. A pair of filters, one for voltage and one for current each have a response determined by complex non-conjugate poles. The response of the filters is such that only the positive or negative half plane of the complex frequency spectrum is passed and provide complex outputs representing the real and imaginary parts of both the current and voltage. At least one indication of a power delivered to a load is computed from the complex current and voltage outputs, which may be the real and/or reactive power.

10-01-2009

20090278720

DELTA-SIGMA ANALOG-TO-DIGITAL CONVERTER CIRCUIT HAVING REDUCED SAMPLED REFERENCE NOISE - A delta-sigma analog-to-digital converter (ADC) circuit improves performance by reducing the amount of noise and other error sampled by the reference switching circuit. The reference switching network is operated intermittently only when the charge on an input integrator exceeds a threshold, thereby preventing the input integrator from saturating, while avoiding needlessly injecting reference noise. The input to the ADC may be a current injected directly into a summing node of the integrator, or may be a voltage supplied through another switching network.

11-12-2009

20090310941

AUDIO CLOCKING IN VIDEO APPLICATIONS - A method of operating an electronic video device such as a DVD player, wherein video clock signals and audio clock signals are derived from a system clock signal using two phase-lock loops, and these video and audio clock signals are used to process encoded video data and encoded audio data, but digital-to-analog conversion of the audio data stream is controlled by the system clock signal rather than the audio clock signals. By using the system clock signal to control the audio digital-to-analog converter (DAC), the DAC avoids the poor performance issues that can arise from jitter introduced into the audio clock signals by the PLL. The system clock signal may be divided by an integer to generate the sampling clock for the audio DAC. In the illustrative embodiment, the system clock signal has a rate which is not an integer multiple of the sample rate of the audio data stream.

12-17-2009

20090322300

HYSTERETIC BUCK CONVERTER HAVING DYNAMIC THRESHOLDS - A hysteretic buck converter provides improved regulation control, in particular for buck converter standby operation. A comparison circuit compares the output voltage of the buck converter to a waveform that is generated from an indication of the output current of the converter, so that the turn-on time of the converter is advanced as the output current demand increases. The resulting action anticipates a reduction in output voltage due to the increased current, preventing an excursion of the output voltage below the ripple voltage minimum. The turn-off time of the converter is controlled by an upper threshold that limits the ripple voltage maximum. The output current indication may be a measurement of output current, or may be a dynamic value calculated from the input voltage and the output voltage waveform.

12-31-2009

20100013050

Compensation Of Field Effect On Polycrystalline Resistors - A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.

01-21-2010

20100019874

Transformer With Split Primary Winding - A transformer includes a core having a first leg, a second leg and a third leg, a split primary winding including first turns about the first leg electrically coupled with second turns about the third leg, and a secondary winding about the second leg. Magnetic flux linking the first turns of the split primary winding and magnetic flux linking the second turns of the primary winding link the secondary winding.

01-28-2010

20100020569

RESONANT SWITCHING POWER CONVERTER WITH ADAPTIVE DEAD TIME CONTROL - A resonant switching power converter having adaptive dead time control provides improved efficiency along with reduced EMI/audible noise and component stresses. A dead time between pulses generated by a switching circuit is adaptively set in conformity with a value of the input voltage to the resonant switching power converter and an indication of a magnitude of the current passing through inductive element of the resonant tank of the converter. The indication of the current magnitude may be the switching frequency of the converter, or a measure of line or load current levels. The dead time can be obtained from a look-up table or computed from the current magnitude and input voltage values.

01-28-2010

20100020570

RESONANT SWITCHING POWER CONVERTER WITH BURST MODE TRANSITION SHAPING - A resonant switching power converter having burst mode transitioning operates during low or zero load conditions with reduced audible noise and component stresses, while improving efficiency. Pulse bursts are generated with a beginning and/or ending pulse duration that differs from mid-burst pulse durations, in order to reduce an amplitude of transients otherwise generated at the beginning and/or end of the bursts. Alternatively, the spacing between the pulses at the beginning and/or end of the bursts may differ from the spacing between the pulses in the middle of the bursts to reduce the transient(s). A number of pulses at the beginning and/or end of the burst can also be set with gradually varying durations, to further reduce component stress and audible vibration in a transformer that couples the resonant tank to the output of the converter.

01-28-2010

20100020573

AUDIBLE NOISE SUPPRESSION IN A RESONANT SWITCHING POWER CONVERTER - Audible noise in resonant switching power converter during low-power burst mode operation is reduced by spreading the spectrum generated by the bursts, thereby reducing the amplitude of audio spectrum peaks in the current supplied through the resonant tank from a switching circuit. The spreading can be accomplished by varying the intervals between the bursts and/or by varying a pulse pattern within the bursts. The pulse pattern within the bursts can be varied by varying the number of pulses in the bursts, the polarity of the initial pulse of the bursts, and/or the duration of pulses within the bursts either uniformly or randomly. The burst pulse pattern may also be selected in alternation from a set of pulse patterns stored in a memory and the selection may be made randomly or systematically.

01-28-2010

20100020579

Power Supply With Accurate Energy Measurement - A power supply includes a rectifier having an AC input and a DC output and a power factor correction (PFC) preregulator, coupled to the rectifier, that increases a power factor of the power supply. The PFC preregulator includes a controller that integrates an input power to determine energy consumption and outputs a signal indicative of the energy consumption.

01-28-2010

20100060202

Lighting System with Lighting Dimmer Output Mapping - A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level.

03-11-2010

20100079125

Current sensing in a switching power converter - A power control system includes a current sense resistor located on an output side of a switching power converter. By locating the current sense resistor on the output side of the switching power converter, the current sense resistor conducts a sense current when a control switch of the switching power converter is nonconductive. Since a duty cycle of the control switch is larger for a low input voltage than for a higher input voltage, the current sense resistor conducts current for a shorter time duration for low input voltages than for higher input voltages. Thus, the root mean square (RMS) of a sense current in the current sense resistor and, thus, power dissipation by the current sense resistor, is lower during low input voltages than power dissipation in conventionally located current sense resistors. The RMS of the sense current is approximately constant across a full range of input voltages.

04-01-2010

20100148677

TIME DIVISION LIGHT OUTPUT SENSING AND BRIGHTNESS ADJUSTMENT FOR DIFFERENT SPECTRA OF LIGHT EMITTING DIODES - In at least one embodiment, brightness multiple LEDs is adjusted by modifying power to subgroups of the multiple LEDs during different times and detecting the brightness of the LEDs during the reductions of power. In at least one embodiment, once the brightness of the LEDs are determined, a controller determines if the brightness meet target brightness values, and, if not, the controller adjusts each LED with the goal meet the target brightness values. In at least one embodiment, a process of modifying power to the subgroups of multiple LEDs over time and adjusting the brightness of the LEDs is referred as “time division and light output sensing and adjusting. Thus, in at least one embodiment, a lighting system includes time division light output sensing and adjustment for different spectrum light emitting diodes (LEDs).

06-17-2010

20100164406

SWITCHING POWER CONVERTER CONTROL WITH TRIAC-BASED LEADING EDGE DIMMER COMPATIBILITY - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period.

07-01-2010

20100164631

ELECTRONIC SYSTEM HAVING COMMON MODE VOLTAGE RANGE ENHANCEMENT - An electronic system generates at least one floating supply voltage, wherein during operation of the circuit the floating supply voltage tracks a common mode voltage of first and second differential input signals. By tracking the common mode voltage, in at least one embodiment, the floating supply voltage adjusts as the common mode voltage changes. Thus, the floating supply voltages can be based upon the peak-to-peak values of the first and second output signals without factoring in the common mode voltage. In at least one embodiment, the electronic system provides the floating supply voltages to an amplifier. The amplifier amplifies the first and second differential input signals and generates differential output signals. A differential sampling circuit samples the differential output signals to cancel the common mode voltage from the differential output signals. In at least one embodiment, an analog-to-digital converter converts the sampled differential output signals into a digital output signal.

07-01-2010

20100171442

Light Emitting Diode Based Lighting System With Time Division Ambient Light Feedback Response - A lighting system includes time division light output sensing and adjustment for ambient light. In at least one embodiment, time division light output sensing involves modulating power to a light emitting diode (LED) set, and the set of LEDs includes one or more LEDs. In at least one embodiment, each LED in the LED set is included in a single lamp, and, in at least one embodiment, the set of LEDs is contained in multiple lamps. In at least one embodiment, for each lamp, a controller modulates power to the LED set by selectively reducing power to the LED set using time division algorithm to allow a light sensor to sense the brightness of ambient light with a reduced contribution from the LED set. In at least one embodiment, a lighting system also includes time division light output sensing and adjustment for different spectra LEDs.

07-08-2010

20100244726

PRIMARY-SIDE BASED CONTROL OF SECONDARY-SIDE CURRENT FOR A TRANSFORMER - A power control system includes a transformer and a controller regulates a current on a secondary-side of the transformer based on a primary-side signal value. In at least one embodiment, the secondary-side current is a current out of a filter coupled to a rectifier and the secondary-side of the transformer and into a load. In at least one embodiment, the primary-side signal value is a sample of a current in the primary-side windings of the transformer. In at least one embodiment, the primary-side signal value represents a sample value of a primary-side transformer current. Proper timing of sampling the primary-side signal value substantially eliminates contributions of a transformer magnetizing current from the primary-side transformer current sample. Sampling the primary-side signal value when contributions of the transformer magnetizing current are substantially eliminated allows at least an average of the secondary-side current to be determined from the primary-side signal value.

09-30-2010

20100253305

SWITCHING POWER CONVERTER CONTROL WITH SPREAD SPECTRUM BASED ELECTROMAGNETIC INTERFERENCE REDUCTION - Power control systems generate electromagnetic interference (EMI). In at least one embodiment, a power control system includes a switching power converter and a controller that utilizes a spread spectrum strategy to reduce peak EMI values of the power control system. The controller generates a power regulation, switch control signal to control an input voltage to output voltage conversion by the switching power converter. The controller modulates the period of the control signal in accordance with the spread spectrum strategy. The spread spectrum strategy is an intentional plan to spread the spectrum of the control signal to reduce peak EMI values, and, thus, reduce the potential for degradation in performance, a malfunction, or failure of an electronic circuit caused by the EMI. The controller also modulates a pulse width of the switch control signal in response to modulation of the period of the control signal to provide power factor correction.

10-07-2010

20100277072

Calibration Of Lamps - In at least one embodiment, a lamp includes a controller configured to generate power control signals for a lamp is also configured to receive lamp calibration data received via one or more power terminals of the lamp. The controller is configured to process the calibration data to calibrate the lamp. In at least one embodiment, the lamp includes one or more light emitting diodes.

11-04-2010

20100308742

Power Control System for Current Regulated Light Sources - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

12-09-2010

20100327765

LOW ENERGY TRANSFER MODE FOR AUXILIARY POWER SUPPLY OPERATION IN A CASCADED SWITCHING POWER CONVERTER - A cascaded power converter having an auxiliary power supply operated from the second switching power stage provides efficient operation by activating the auxiliary power supply early in the startup process. A low energy transfer operating mode is initiated in the second switching power stage to charge the auxiliary power supply output without generating significant disruption at the load. After the first switching power stage is started and the intermediate node voltage has increased to a level sufficient to operate the second switching power stage, the final switching power stage enters a normal operating mode. The low energy transfer operating mode has a substantially reduced switching rate and pulse width from that of the normal operating mode.

12-30-2010

20100327838

SWITCHING POWER CONVERTER WITH CURRENT SENSING TRANSFORMER AUXILIARY POWER SUPPLY - A switching power converter having a current sensing transformer providing input to an auxiliary power supply provides efficient current sensing, while reducing the cost of the magnetic coupling element. The auxiliary power supply and current sense circuit both receive input from a secondary winding of a current sensing transformer having a primary winding coupled in series with the converter's main magnetic coupling element. To provide accurate sensing, the magnetization the current sensing transformer is accounted for. The magnetization is compensated for in the current sensing result, current sensing is performed during a part of the cycle in which charging of the auxiliary power supply is disabled, or the core of the current sensing transformer is made large, raising its mutual inductance. In another alternative technique, a circuit node can be pre-charged to a value that cancels the offset due to the magnetization current.

12-30-2010

20100328976

CASCODE CONFIGURED SWITCHING USING AT LEAST ONE LOW BREAKDOWN VOLTAGE INTERNAL, INTEGRATED CIRCUIT SWITCH TO CONTROL AT LEAST ONE HIGH BREAKDOWN VOLTAGE EXTERNAL SWITCH - An electronic system includes a low breakdown voltage (LBV) switch internal to an integrated circuit controller to control conductivity of an external, high breakdown voltage (HBV) switch. In at least one embodiment, the internal LBV switch and a cascode configuration of the LBV and HBV switches allow the controller to control the LBV switch and the HBV switch using an internal (“on-chip”) control signal. In at least one embodiment, the LBV switch and the cascode configuration of the HBV switch also allows the controller to control the LBV and HBV switches with more accuracy and less parasitic losses relative to directly controlling the HBV switch. Thus, in at least one embodiment, the low breakdown voltage switch is fabricated as part of an integrated circuit controller, and the high breakdown voltage switch is fabricated separately and located external to the integrated circuit controller.

12-30-2010

20110016344

AUDIO CLOCKING IN VIDEO APPLICATIONS - A method of operating an electronic video device such as a DVD player, wherein video clock signals and audio clock signals are derived from a system clock signal using two phase-lock loops, and these video and audio clock signals are used to process encoded video data and encoded audio data, but digital-to-analog conversion of the audio data stream is controlled by the system clock signal rather than the audio clock signals. By using the system clock signal to control the audio digital-to-analog converter (DAC), the DAC avoids the poor performance issues that can arise from jitter introduced into the audio clock signals by the PLL. The system clock signal may be divided by an integer to generate the sampling clock for the audio DAC. In the illustrative embodiment, the system clock signal has a rate which is not an integer multiple of the sample rate of the audio data stream.

01-20-2011

20110032734

CASCADED SWITCHING POWER CONVERTER FOR COUPLING A PHOTOVOLTAIC ENERGY SOURCE TO POWER MAINS - A cascaded switching power converter for coupling a photovoltaic (PV) energy source to power mains provides a high-efficiency and a potentially simple control mechanism for AC solar energy conversion systems. The PV energy source charges a capacitive storage element through a DC-DC converter, and an inverter couples energy from the capacitive storage element to the mains supply. The DC-DC converter is controlled so that ripple present on the capacitive storage element due to current drawn by the inverter is not reflected at the input of the DC-DC converter, which is accomplished by varying the conversion ratio of the DC-DC converter with the ripple voltage present across the capacitor. The average voltage of the capacitor can also be increased with increases in the available power output from the PV energy source, so that a corresponding increase in power is transferred to the mains supply.

02-10-2011

20110050472

DELTA-SIGMA ANALOG-TO-DIGITAL CONVERTER (ADC) HAVING A SERIALIZED QUANTIZER OUTPUT - A delta-sigma analog-to-digital converter (ADC) having a serialized quantizer output has a data rate greater than a quantization rate of the delta-sigma modulator, but less than a bit rate determined by the product of the number of bits required to represent the input to a feedback digital-to-analog converter and the quantization rate. Additional information can be encoded in the serial bit stream by selection among redundant codes based on the value of the additional information. The serial bit stream may encode differences between successive quantizer output samples and the additional information may include the absolute value of the quantizer output, synchronization information and/or framing information for distinguishing data corresponding to multiple ADC input channels.

03-03-2011

20110075448

SWITCHING POWER CONVERTER CONTROLLER WITH DIRECT CURRENT TRANSFORMER SENSING - A power control system includes a current transformer to step down a switch current of a switching power converter. In at least one embodiment, the stepped down current is received by a switching power converter controller. Since the current is received by the controller, the current is not converted into a voltage prior to receipt by the controller in order for the controller to monitor an inductor current of the switching power converter. In at least one embodiment, the controller compares the stepped down switch current with a reference current. In at least one embodiment, the controller includes a voltage converter to convert the switch current into a voltage within the controller. The controller compares the voltage representing the switch current with a reference voltage. The controller can use the current or voltage comparisons to control power factor correction and output voltage regulation of a switching power converter.

03-31-2011

20110075723

Thermal Feedback for Switch Mode Amplification - A thermal sensor at the output of a switching amplifier senses heat dissipation at the output switch. If an overheating condition is sensed, gain of the digital input signal is lowered to reduce output power of the audio output signal.

03-31-2011

20110103111

Switching Power Converter With Efficient Switching Control Signal Period Generation - A power control system includes a switching power converter and a controller, and the controller responds to a time-varying voltage source signal by generating a switch control signal having a period that varies in accordance with at least one of the following: (i) the period of the switch control signal trends inversely to estimated power delivered to a load coupled to the switching power converter, (ii) the period of the switch control signal trends inversely to instantaneous voltage levels of the voltage source signal, and (iii) the period of the switch control signal trends directly with a line voltage level of the time-varying voltage source signal. In at least one embodiment, the controller achieves an efficient correlation between the switching period with associated switching losses and the instantaneous power transferred to the switching power converter while providing power factor correction (PFC).

05-05-2011

20110210674

Multi-LED Control - A LED driver and controller system utilizes switches to parallel connect to respective sets of one or more LEDs and a current source to provide efficient control of the LEDs. In at least one embodiment, the LEDs are connected in series. An LED controller of the LED driver and controller system

09-01-2011

20110291587

Multi-Function Duty Cycle Modifier - A system and method modify phase delays of a periodic, phase modulated mains voltage to generate at least two independent items of information during each cycle of the periodic input signal. The independent items of information can be generated by, for example, independently modifying leading edge and trailing edge phase delays of each half cycle phase modulated mains voltage. Modifying phase delays for the leading and trailing edges of each half cycle of the phase modulated mains voltage can generate up to four independent items of data. The items of data can be converted into independent control signals to, for example, control drive currents to respective output devices such as light sources to provide multiple items of information per cycle.

12-01-2011

20120025608

MULTIPLE POWER SOURCES FOR A SWITCHING POWER CONVERTER CONTROLLER - An electronic system includes two power supplies to supply an operating voltage to a switching power converter. The first power supply, referred to as a start-up power supply, includes a first source follower transistor to conduct a start-up current for a controller and supply an operating voltage for the controller. The controller controls operation of the switching power converter. A second power supply, referred to as an auxiliary power supply, includes a second source follower transistor to conduct a steady-state operational current for the controller and supply an operating voltage for the controller. In at least one embodiment, once the second power supply begins supplying the operating voltage to the controller, the start-up power supply automatically ceases supplying the start-up current to the controller.

02-02-2012

20120025722

SECONDARY-SIDE ALTERNATING ENERGY TRANSFER CONTROL WITH INVERTED REFERENCE AND LED-DERIVED POWER SUPPLY - A single magnetic storage element is used to provide power to multiple lighting devices, which may be strings of light-emitting diodes (LEDs) of different color. A switching circuit controls alternating application of energy among the multiple lighting devices and another switching circuit may charge the primary winding to different energy levels to control the intensity of the multiple lighting devices. In particular, the multiple lighting devices may be controlled to provide a desired color profile while dimming the lighting devices, while requiring only a single magnetic storage element for supplying energy to the lighting devices.

02-02-2012

20120025724

Coordinated Dimmer Compatibility Functions - A system and method includes a controller that is configured to coordinate (i) a low impedance path for a dimmer current, (ii), control of switch mode power conversion and (iii) an inactive state to, for example, to allow a dimmer to function normally from cycle to cycle of an alternating current (AC) supply voltage. In at least one embodiment, the dimmer functions normally when the dimmer conducts at a correct phase angle indicated by a dimmer input setting and avoids prematurely resetting while conducting. In at least one embodiment, by coordinating functions (i), (ii), and (iii), the controller controls a power converter system that is compatible with a triac-based dimmer. In at least one embodiment, the controller coordinates functions (i), (ii), and (iii) in response to a particular dimming level indicated by a phase cut, rectified input voltage supplied to the power converter system.

02-02-2012

20120025729

POWERING HIGH-EFFICIENCY LIGHTING DEVICES FROM A TRIAC-BASED DIMMER - A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer predicts a zero-crossing time of the AC power line supplying the dimmer and causes a glue impedance to be imposed at the output of the dimmer starting at the time of the zero-crossing, so that the timer in the dimmer will operate properly to generate the turn-on event at the correct time. At turn-on, a lower level of impedance is presented to absorb the energy associated with the turn-on event. A higher level of impedance may be presented after the energy is absorbed until all of the energy needed for the cycle is transferred. Then, a high impedance state is maintained until the next zero-crossing time. The impedance control may be provided by non-uniform operation of a power converter that supplies the lighting devices, or by a combination of non-uniform power converter operation and dissipative loading.

02-02-2012

20120025733

DIMMING MULTIPLE LIGHTING DEVICES BY ALTERNATING ENERGY TRANSFER FROM A MAGNETIC STORAGE ELEMENT - A single magnetic storage element is used to provide power to multiple lighting devices, which may be strings of light-emitting diodes (LEDs) of different color. A switching circuit controls alternating application of energy among the multiple lighting devices and another switching circuit may charge the primary winding to different energy levels to control the intensity of the multiple lighting devices. In particular, the multiple lighting devices may be controlled to provide a desired color profile while dimming the lighting devices, while requiring only a single magnetic storage element for supplying energy to the lighting devices.

02-02-2012

20120025736

INTEGRATED CIRCUIT SWITCHING POWER SUPPLY CONTROLLER WITH SELECTABLE BUCK MODE OPERATION - An integrated circuit (IC) controller for a switching power supply has a selectable operating mode for supporting multiple switching power supply topologies. The IC controls current by controlling a cycle rate of the switching power supply to provide a constant or variable output current, which may be provided to lighting devices such as light-emitting diodes (LEDs). The selectable operating mode includes at least a buck converter operating mode and another operating mode, which may be a flyback converter operating mode.

02-02-2012

20120043913

Dimmer Output Emulation - A lighting system includes a dimmer output voltage emulator to cause a power converter interface circuit to generate an emulated dimmer output voltage. In at least one embodiment, the emulated dimmer output voltage corresponds to an actual dimmer output voltage but is unaffected by non-idealities in the dimmer output voltage, such as premature shut-down of a triac-based dimmer. By generating an emulated dimmer output voltage, the energy delivered to a load, such as a lamp, corresponds to a dimming level setting.

02-23-2012

20120081099

SUPPLY INVARIANT BANDGAP REFERENCE SYSTEM - An electronic reference-signal generation system includes a supply invariant bandgap reference system that generates one or more bandgap reference signals that are substantially unaffected by bulk error currents. In at least one embodiment, the bandgap reference generates a substantially invariant bandgap reference signals for a range of direct current (DC) supply voltages. Additionally, in at least one embodiment, the bandgap reference system provides substantially invariant bandgap reference signals when the supply voltage varies due to alternating current (AC) voltages. In at least one embodiment, the bandgap reference system generates a bandgap reference voltage VBG, a “proportional to absolute temperature” (PTAT) current (“i

04-05-2012

20120091904

Hybrid Gas Discharge Lamp-Led Lighting System - A lighting system and method combine at least one LED and at least one gas discharge lamp within a common housing. The lighting system includes a control system to dependently operate each LED and each gas discharge lamp during overlapping, non-identical periods of time. In at least one embodiment, the control system can provide light output by activating LEDs during gas discharge preheating operations and thus extend the useful life of each gas discharge lamp. When dimming the lighting system, the control system can reduce current to the gas discharge lamps and one or more gas discharge lamps can be phased out as dimming levels decrease. As dimming levels decrease, one or more of the LEDs can be activated or groups of LEDs can be phased in to replace the light output of the dimmed gas discharge lamps. Thus, the lighting system can reduce power consumption at low dimming levels.

04-19-2012

20120112638

Thermal Management In A Lighting System Using Multiple, Controlled Power Dissipation Circuits - A lighting system includes a controller that is configured to provide thermal management for the lighting system by distributing excess energy in the lighting system through multiple power dissipation circuits. In at least one embodiment, the lighting system is a phase cut compatible, dimmable lighting system having one or more light sources selected from a group consisting of at least one light emitting diode and at least one compact fluorescent lamp. In at least one embodiment, the controller is configured to control the plurality of power dissipation circuits in accordance with a thermal management strategy to dissipate the excess energy in the phase cut compatible, dimmable lighting system. The particular thermal management strategy is a matter of design choice. The power distribution circuits include two of more of: a controlled switch path power dissipation circuit, a controlled link path power dissipation circuit, and a controlled flyback path power dissipation circuit.

05-10-2012

20120112639

Controlled Power Dissipation In A Link Path In A Lighting System - In at least one embodiment, a lighting system includes a link path power dissipation circuit to actively and selectively control power dissipation of excess energy in a switching power converter of the lighting system. The link path power dissipation circuit dissipates power through a link path of the switching power converter by controlling a link current of the switching power converter. In at least one embodiment, the controller controls the link path power dissipation circuit to limit the link current with a current source and dissipate power in the current source. In at least one embodiment, the link path power dissipation circuit includes a switch to limit the link current and dissipate power in the link path.

05-10-2012

20120112651

DUTY FACTOR PROBING OF A TRIAC-BASED DIMMER - A power supply circuit for operating high-efficiency lighting devices from a thyristor-controlled dimmer determines the dimming value, i.e., the dimmer duty factor by periodically probing the dimmer output. A minimum conductance is applied across the output of the dimmer during probing intervals that begin at the turn-on time of the dimmer and last until enough information has been gathered to correctly predict a next zero crossing of the AC line voltage that supplies the input of the dimmer. The dimming value is determined from the time interval between the predicted zero-crossing and a next turn-on time of the dimmer. The probing can be performed at intervals of an odd number of half-cycles of the AC line frequency so that a DC offset is not introduced within internal timing circuits of the dimmer. The AC line frequency can also be determined from a time interval between the predicted zero crossings.

05-10-2012

20120112665

Controlled Power Dissipation In A Lighting System - In at least one embodiment, a lighting system includes one, some, or all of a switch path, link path, and flyback path power dissipation circuits to actively and selectively control power dissipation of excess energy in a switching power converter of the lighting system. The flyback path power dissipation circuit dissipates power through a flyback path of the switching power converter. In at least one embodiment, the lighting system controls power dissipation through the flyback path by controlling a transformer primary current in the flyback path and, for example, limiting the primary current with a current source and dissipating power in the flyback switch and the current source.

05-10-2012

20120119669

Trailing Edge Dimmer Compatibility With Dimmer High Resistance Prediction - In at least one embodiment, an electronic system includes a controller, and the controller provides compatibility between an electronic light source and a trailing edge dimmer. In at least one embodiment, the controller is capable of predicting an estimated occurrence of a trailing edge of a phase cut AC voltage and accelerating a transition of the phase cut AC voltage from the trailing edge to a predetermined voltage threshold. In at least one embodiment, the controller predicts an estimated occurrence of the trailing edge of the phase cut AC voltage on the basis of actual observations from one or more previous cycles of the phase cut AC voltage.

05-17-2012

20120153858

Switching Parameter Based Discontinuous Mode-Critical Conduction Mode Transition - An electronic system includes a controller to provide at least dual-mode conduction control of a switching power converter. In at least one embodiment, the controller is capable to control transitions between discontinuous conduction mode (DCM) and critical conduction mode (CRM) of the switching power converter using a measured switching time parameter having a value corresponding with an approximately peak voltage of a time-varying supply voltage supplied to the switching power converter. In at least one embodiment, the controller dynamically compensates for changing parameters of the electronic system by dynamically determining a minimum non-conductive time of the control switch of the switching power converter using the measured switching time parameter value at approximately the peak of the supply voltage of the supply voltage.

06-21-2012

20120181946

Lighting System With Power Factor Correction Control Data Determined From A Phase Modulated Signal - A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used by the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal.

07-19-2012

20120229046

Power Control System for Current Regulated Light Sources - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

09-13-2012

20120274225

Controller Customization System With Phase Cut Angle Communication Customization Data Encoding - A controller is configured to generate one or more power control signals for a lamp to supply power to the lamp from a supply voltage. The controller is further configured to receive customization data encoded in the supply voltage. Thus, in at least one embodiment, the controller receives the customization data via one or more power terminals of the lamp. Phase cut angles in the supply voltage provided to the controller encode the customization data, and each phase cut angle encodes N symbols of data. N is an integer greater than or equal to one (1). In at least one embodiment, the customization data alters the controller from one state to another state in accordance with data represented by phase cuts in the supply voltage that encode the customization data. Examples of customization data include calibration data and configuration data.

11-01-2012

20120286684

Controlled Power Dissipation In A Switch Path In A Lighting System - A lighting system includes one or more methods and systems to control dissipation of excess power in the lighting system when the power into a switching power converter from a leading edge, phase-cut dimmer is greater than the power out of the switching power converter. In at least one embodiment, the lighting system includes a controller that controls dissipation of excess energy in the lighting system to prevent a premature disconnection of the phase-cut dimmer. In at least one embodiment, the controller actively controls power dissipation by generating one or more signals to actively and selectively control power dissipation in the lighting system. By actively and selectively controlling power dissipation in the lighting system, the controller intentionally dissipates power when the power into the lighting system should be greater than the power out to a lamp of the lighting system. In at least one embodiment, the controller creates one or more intermixed and/or interspersed power dissipation phases with one or more switching power converter charging and/or flyback phases.

11-15-2012

20120286690

Lighting System With Power Factor Correction Control Data Determined From A Phase Modulated Signal - A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used by the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal.

11-15-2012

20120286826

Switching Power Converter Input Voltage Approximate Zero Crossing Determination - In at least one embodiment, the controller senses a leading edge, phase cut AC input voltage value to a switching power converter during a cycle of the AC input voltage. The controller senses the voltage value at a time prior to a zero crossing of the AC input voltage and utilizes the voltage value to determine the approximate zero crossing. In at least one embodiment, by determining an approximate zero crossing of the AC input voltage, the controller is unaffected by any disturbances of the dimmer that could otherwise make detecting the zero crossing problematic. In at least one embodiment, the controller approximates the AC input voltage using a function that estimates a waveform of the AC input voltage and determines the approximate zero crossing of the AC input voltage from the approximation of the AC input voltage.

11-15-2012

20120299501

Switching Power Converter Control With Triac-Based Leading Edge Dimmer Compatibility - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period.

11-29-2012

20120308024

BANDLIMITING ANTI-NOISE IN PERSONAL AUDIO DEVICES HAVING ADAPTIVE NOISE CANCELLATION (ANC) - A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to measure the output of the transducer in order to control the adaptation of the anti-noise signal and to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit that performs the adaptive noise canceling (ANC) function also either adjusts the frequency response of the anti-noise signal with respect to the reference microphone signal, and/or by adjusting the response of the adaptive filter independent of the adaptation provided by the reference microphone signal.

12-06-2012

20120327690

Primary-Side Based Control Of Econdary-Side Current For A Transformer - A power control system includes a transformer and a controller regulates a current on a secondary-side of the transformer based on a primary-side signal value. In at least one embodiment, the secondary-side current is a current out of a filter coupled to a rectifier and the secondary-side of the transformer and into a load. In at least one embodiment, the primary-side signal value is a sample of a current in the primary-side windings of the transformer. In at least one embodiment, the primary-side signal value represents a sample value of a primary-side transformer current. Proper timing of sampling the primary-side signal value substantially eliminates contributions of a transformer magnetizing current from the primary-side transformer current sample. Sampling the primary-side signal value when contributions of the transformer magnetizing current are substantially eliminated allows at least an average of the secondary-side current to be determined from the primary-side signal value.

12-27-2012

20130002156

TRANSFORMER-ISOLATED LED LIGHTING CIRCUIT WITH SECONDARY-SIDE DIMMING CONTROL - A transformer isolated LED lighting circuit supplies current from a secondary-side storage capacitor to one or more LED strings in conformity with one or more dimming values. The dimming values are communicated through the transformer by patterns or codes provided in pulses of a power converter circuit that charges the storage capacitor from the primary side of the transformer, or alternatively by a special modulated signal provided in addition to the switching pulses.

01-03-2013

20130002163

Input Voltage Sensing For A Switching Power Converter And A Triac-Based Dimmer - An electronic lighting system and method described herein control energy provided to an electronic lighting device, such as one or more light-emitting diodes (LEDs) and/or compact fluorescent lamps (CELs), of the electronic lighting system. A triac-based dimmer phase cuts a line voltage provided to the electronic lighting system. A controller of the electronic lighting system utilizes a probing system to overcome idiosyncrasies of the triac-based dimmer to allow the controller to probe and sense the line voltage. To reduce energy consumption, rather than probing each cycle of the output voltage of the triac-based dimmer, the controller periodically or intermittently probes the output voltage of the triac-based dimmer.

01-03-2013

20130069561

COLOR MIXING OF ELECTRONIC LIGHT SOURCES WITH CORRELATION BETWEEN PHASE-CUT DIMMER ANGLE AND PREDETERMINED BLACK BODY RADIATION FUNCTION - A lighting system includes methods and systems to mix colors of light emitted from at least two LED emitters. In at least one embodiment, the lighting system includes a controller that responds to phase-cut angles of the dimming signal and correlates the phase-cut angles with a predetermined black body radiation function to dynamically adjust a color spectra of the mixed light in response to changes in phase cut angles of the phase-cut dimming level signal. In at least one embodiment, the controller utilizes the predetermined black body radiation function to dynamically adjust the color spectra of the mixed, emitted light in response to changes in phase cut angles of a phase-cut dimming level signal. In at least one embodiment, the predetermined black body radiation function specifies correlated color temperatures (CCTs) that model the CCTs of an actual non-LED based lamp, such as an incandescent lamp.

03-21-2013

20130155728

Isolation of Secondary Transformer Winding Current During Auxiliary Power Supply Generation - An electronic system and method include a controller to actively control power transfer from a primary winding of a switching power converter to an auxiliary-winding of an auxiliary power supply. The switching power converter is controlled and configured such that during transfer of power to the auxiliary-winding, the switching power converter does not transfer charge to one or more secondary-windings of the switching power converter. Thus, the switching power converter isolates one or more secondary transformer winding currents from an auxiliary-winding current. By isolating the charge delivered to the one or more secondary-windings from charge delivered to the auxiliary-winding, the controller can accurately determine an amount of charge delivered to the secondary-windings and, thus, to a load.

06-20-2013

20130221871

MIXED LOAD CURRENT COMPENSATION FOR LED LIGHTING - In at least one embodiment, a system and method provide current compensation in a lighting system by controlling a lamp current to prevent a current through a triac-based dimmer from undershooting a holding current value. In at least one embodiment, at least one of the lamps includes a controller that controls circuitry in the lamp to draw more lamp current for a period of time than needed to illuminate a brightness of the lamp at a level corresponding to particular phase-cut angle of the supply voltage. By drawing more current than needed, the controller increases the dimmer current during the period of time to prevent the dimmer current from falling below the holding current value. In at least one embodiment, the period of time corresponds to a compensating pulse of the lamp current at a time when the dimmer current would otherwise fall below the holding current value.

08-29-2013

20130271027

Lighting System With Power Factor Correction Control Data Determined From A Phase Modulated Signal - A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used by the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays. are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal.

10-17-2013

20130300309

LED Lighting System with Accurate Current Control - A light emitting diode (LED) lighting system and method are disclosed, The LED lighting system and method include an LED controller to accurately control a current in an LED system. The LED controller includes components to calculate, based on the current and an active time period of an LED current time period, an actual charge amount delivered to the LED system wherein the LED current time period is duty cycle modulated at a rate of greater than fifty (50) Hz and to utilize the actual charge amount to modify and provide a desired target charge amount to be delivered during a future active time period of the LED current time period, The LED system and method further involve components to compare the actual charge amount to a desired charge amount for the active time period and compensate for a difference between the actual charge amount and the desired charge amount during the future active time period.

11-14-2013

20130314017

Circuit and Method for Calibration of Sensorless Control of a Permanent Magnet Brushless Motor during Start-up - A system for controlling motor switching in a sensorless BLDC having a stator with three stator windings and a permanent magnet rotor. The system includes a controller unit comprising a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage controlled by the controller unit has a plurality of switches and drives two windings of the three stator windings with a pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit calculates a threshold at which the power stage will change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses the threshold.

11-28-2013

20130342123

TRAILING EDGE DIMMER COMPATIBILITY WITH DIMMER HIGH RESISTANCE PREDICTION - In at least one embodiment, an electronic system includes a controller, and the controller provides compatibility between an electronic light source and a trailing edge dimmer. In at least one embodiment, the controller is capable of predicting an estimated occurrence of a trailing edge of a phase cut AC voltage and accelerating a transition of the phase cut AC voltage from the trailing edge to a predetermined voltage threshold. In at least one embodiment, the controller predicts an estimated occurrence of the trailing edge of the phase cut AC voltage on the basis of actual observations from one or more previous cycles of the phase cut AC voltage.

12-26-2013

20130342130

LIGHTING SYSTEM WITH LIGHTING DIMMER OUTPUT MAPPING - A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level.

12-26-2013

20130342141

DETERMINING COMMUTATION POSITION FOR A SENSORLESS PERMANENT MAGNET BRUSHLESS MOTOR AT LOW OR ZERO SPEED USING AN ASYMMETRIC DRIVE PATTERN - A system is disclosed for controlling motor switching in a sensorless BLDC motor having a set of three stator windings. A controller unit includes a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage having a plurality of switches receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with an asymmetric pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit also communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

12-26-2013

20130342145

SYSTEM AND METHOD FOR ISOLATING THE UNDRIVEN VOLTAGE OF A PERMANENT MAGNET BRUSHLESS MOTOR FOR DETECTION OF ROTOR POSITION - The system and method disclose for the controlling of sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A motor controller controls a power stage that drives two windings of a set of three windings in the motor with pulse width modulated signal. A plurality of voltage values on an undriven winding of the set of three windings are sampled within a window of time, wherein a period beginning when the driven windings are energized and ending when the driven windings are de-energized encompasses the window of time. The sampled voltage values are processed. When the processed voltage values exceed a threshold, the motor controller changes which two windings are driven.

12-26-2013

20130342146

METHOD AND SYSTEM FOR SWITCHING BETWEEN DIFFERENT TYPES OF OPERATION OF A SENSORLESS PERMANENT MAGNET BRUSHLESS MOTOR AT LOW OR ZERO SPEED TO DETERMINE ROTOR POSITION - The system and method disclose for the controlling of motor switching. The system includes a controller unit having a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage has a plurality of switches and receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with a multi-state pulse and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

12-26-2013

20140009078

SYSTEMS AND METHODS FOR LOW-POWER LAMP COMPATIBILITY WITH A TRAILING-EDGE DIMMER AND AN ELECTRONIC TRANSFORMER - In accordance with these and other embodiments of the present disclosure, a system and method for providing compatibility between a load and a secondary winding of an electronic transformer driven by a trailing-edge dimmer may include predicting based on an electronic transformer secondary signal an estimated occurrence of a high-resistance state of the trailing-edge dimmer, wherein the high-resistance state occurs when the trailing-edge dimmer begins phase-cutting an alternating current voltage signal and operating the load in a high-current mode for a period of time immediately prior to the estimated occurrence of the high-resistance state.

01-09-2014

20140009079

SYSTEMS AND METHODS FOR LOW-POWER LAMP COMPATIBILITY WITH A LEADING-EDGE DIMMER AND A MAGNETIC TRANSFORMER - A system and method for providing compatibility between a load and a secondary winding of a magnetic transformer driven at its primary winding by a trailing-edge dimmer may include determining from a magnetic transformer secondary signal a period of a half-line cycle of an output signal of the dimmer, determining from the magnetic transformer secondary signal an estimated occurrence of an end of a phase-cut angle of the dimmer, and generating a driving signal to the load based on the period and the estimated occurrence of the end of the phase-cut angle. A lamp assembly may include a lamp for generating light and a controller for controlling operation of the lamp, the controller comprising a timing control circuit for determining a period of a periodic signal received by the lamp assembly.

01-09-2014

20140009082

SYSTEMS AND METHODS FOR DETERMINING A TYPE OF TRANSFORMER TO WHICH A LOAD IS COUPLED - An apparatus may include a controller to provide compatibility between a load and a secondary winding of a transformer driven at its primary winding by a dimmer, wherein the controller is configured to: determine from a transformer secondary signal whether the transformer comprises a magnetic transformer or an electronic transformer; and select a compatibility mode of operation from a plurality of modes of operation based on the determination of whether the transformer comprises a magnetic transformer or an electronic transformer. A method for providing compatibility between a load and a secondary winding of a transformer driven at its primary winding by a dimmer may include determining from a transformer secondary signal whether the transformer comprises a magnetic transformer or an electronic transformer and selecting a compatibility mode of operation from a plurality of modes of operation based on the determination of whether the transformer comprises a magnetic transformer or an electronic transformer.

01-09-2014

20140019247

SYSTEMS AND METHODS FOR DETERMINING LOCATION OF A MOBILE DEVICE BASED ON AN AUDIO SIGNAL - A mobile device includes a display, a microphone, and a controller all within an enclosure sized and shaped such that the enclosure is readily transported on a person of a user of the mobile device. The microphone is configured to receive an audio signal from an audio signal source. The controller is coupled to the microphone and the display, and configured to, based at least on information included in the audio signal, determine a delay between a transmission of the audio signal from the audio signal source to receipt of the audio signal by the microphone. The controller is further configured to, based at least on the delay, determine a geographical location of the mobile device. The controller is also configured to, based on the geographical location of the mobile device, display geographical information to the display indicative of the geographical location.

01-16-2014

20140042926

Power Control System for Current Regulated Light Sources - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

02-13-2014

20140055055

POWER CONVERSION WITH CONTROLLED CAPACITANCE CHARGING INCLUDING ATTACH STATE CONTROL - An electronic system includes a controller that actively controls a rate of charging and discharging of an energy storage capacitor to maintain compatibility with a dimmer. The controller actively controls charging of a capacitor circuit in a switching power converter to a first voltage level across the capacitor circuit. The controller further allows the capacitor to discharge to obtain a second voltage level across the capacitor circuit. The second voltage level is sufficient to draw a current through a phase-cut dimmer to prevent the dimmer from prematurely resetting. The first voltage is sufficient to allow the capacitor to discharge to the second voltage level during each cycle of the line voltage.

02-27-2014

20140077721

POWERING HIGH-EFFICIENCY LIGHTING DEVICES FROM A TRIAC-BASED DIMMER - A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer operates a switching power circuit during active portions of half-cycles of the AC line voltage source that supplies the dimmer. A control circuit determines the durations of the active portions such that sufficient energy is transferred to operate the lighting devices until a next half-cycle of the AC line voltage, at which time the active portion of the half-cycle is terminated. A high impedance level is presented to the output of the dimmer until the next half-cycle commences.

03-20-2014

20140140560

SYSTEMS AND METHODS FOR USING A SPEAKER AS A MICROPHONE IN A MOBILE DEVICE - In accordance with methods and systems of the present disclosure, a mobile device may include an enclosure adapted such that the enclosure is readily transported by a user of the mobile device, a speaker associated with the enclosure for generating sound, and a controller within the enclosure, communicatively coupled to the speaker. The controller may be configured to receive a signal from the speaker, the signal induced at least in part by sound incident on the speaker other than sound generated by the speaker and process the signal.

05-22-2014

20140167639

SYSTEMS AND METHODS FOR LOW-POWER LAMP COMPATIBILITY WITH A LEADING-EDGE DIMMER AND AN ELECTRONIC TRANSFORMER - Methods and systems to provide compatibility between a load and a secondary winding of an electronic transformer driven by a leading-edge dimmer may include: (a) responsive to determining that energy is available from the electronic transformer, drawing a requested amount of power from the electronic transformer thus transferring energy from the electronic transformer to an energy storage device in accordance with the requested amount of power; and (b) transferring energy from the energy storage device to the load at a rate such that a voltage of the energy storage device is regulated within a predetermined voltage range.

06-19-2014

20140167652

SYSTEMS AND METHODS FOR CONTROLLING A POWER CONTROLLER - In accordance with systems and methods of the present disclosure, an apparatus may include a power converter and a controller. The controller may be configured to monitor a voltage at an input of the power converter, cause the power controller to transfer energy from the input to a load at a target current, decrease the target current responsive to determining that the voltage is less than or equal to an undervoltage threshold, and increase the target current responsive to determining that the voltage is greater than or equal to a maximum threshold voltage.

06-19-2014

20140211953

BANDLIMITING ANTI-NOISE IN PERSONAL AUDIO DEVICES HAVING ADAPTIVE NOISE CANCELLATION (ANC) - A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to measure the output of the transducer in order to control the adaptation of the anti-noise signal and to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit that performs the adaptive noise canceling (ANC) function also either adjusts the frequency response of the anti-noise signal with respect to the reference microphone signal, and/or by adjusting the response of the adaptive filter independent of the adaptation provided by the reference microphone signal.

07-31-2014

20140252975

Reduction of Supply Current Variations Using Compensation Current Control - A power distribution system and method includes a controller that is configured to control a switching power converter. In at least one embodiment, the controller includes a compensation current control circuit to control a compensation current that reduces and, in at least one embodiment, approximately eliminates variations in current drawn by the controller during a particular operational time period. In at least one embodiment, the power distribution system is a lamp that includes the controller, a switching power converter, and one or more light sources, such as light emitting diodes.

09-11-2014

20140252981

Utilizing Secondary-Side Conduction Time Parameters of a Switching Power Converter to Provide Energy to a Load - A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load.

09-11-2014

20140265893

HIGH-EFFICIENCY LIGHTING DEVICES HAVING DIMMER AND/OR LOAD CONDITION MEASUREMENT - A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer includes a power converter for powering the high-efficiency lighting devices from input terminals of the circuit. The circuit also includes a control circuit that controls the input current drawn by the input terminals at least while the power converter transfers energy to the lighting devices. The circuit also includes a sensing circuit that determines or measures at least one attach current characteristic at the input terminals and stores an indication of the characteristic for subsequent operation of the control circuit.

09-18-2014

20140265916

Controlled Electronic System Power Dissipation via an Auxiliary-Power Dissipation Circuit - An electronic system and method include a controller to actively control transfer of excess energy to an auxiliary-winding of an auxiliary power dissipation circuit. The excess energy is a transfer of energy from a primary winding of a switching power converter to the auxiliary-winding of the auxiliary power dissipation circuit. In at least one embodiment, the electronic system is a lighting system that includes a triac-based dimmer. The excess energy is energy drawn through the primary-side winding of the switching power converter to provide operational compatibility between a dimmer through which a power supply provides energy to the switching power converter and a load to which the switching power converter provides energy.

09-18-2014

20140265933

SYSTEM AND METHOD FOR LEARNING DIMMER CHARACTERISTICS - Systems and methods for learning dimmer characteristics provide improved efficiency in operating lighting devices. In one embodiment, an apparatus includes a lamp controller that is configured to monitor voltage information associated with one or more lamps or a dimmer of a system, adjust one or more parameters of an attach current profile in conformity with the voltage information to arrive at a selected attach current profile, and apply within the system the selected attach current profile.

09-18-2014

20140270312

SYSTEMS AND METHODS FOR USING A SPEAKER AS A MICROPHONE IN A MOBILE DEVICE - In accordance with methods and systems of the present disclosure, a mobile device may include an enclosure adapted such that the enclosure is readily transported by a user of the mobile device, a speaker associated with the enclosure for generating sound, and a controller within the enclosure, communicatively coupled to the speaker. The controller may be configured to receive a signal from the speaker, the signal induced at least in part by sound incident on the speaker other than sound generated by the speaker and process the signal.

09-18-2014

20140294182

SYSTEMS AND METHODS FOR LOCATING AN ERROR MICROPHONE TO MINIMIZE OR REDUCE OBSTRUCTION OF AN ACOUSTIC TRANSDUCER WAVE PATH - An apparatus may include an acoustic transducer, a housing, a microphone, and an acoustical conduit. The acoustic transducer may include a diaphragm having a front and a back, the diaphragm configured to mechanically vibrate in response to an audio signal, thereby producing sound from the front of the diaphragm. The housing may be configured to mechanically support the acoustic transducer such that the front faces an exterior of the housing and the back faces an interior of the housing. The microphone may be disposed in the interior of the housing and may be configured to sense combined sound produced by the acoustic transducer and ambient sound proximate to the acoustic transducer. The acoustical conduit may be coupled to and extend from the microphone and pass adjacent the acoustic transducer such that the microphone senses sound proximate to the front of the diaphragm.

10-02-2014

20140301571

SYSTEMS AND METHODS FOR GENERATING A DIGITAL OUTPUT SIGNAL IN A DIGITAL MICROPHONE SYSTEM - In accordance with embodiments of the present disclosure, a digital microphone system may include a microphone transducer and a digital processing system. The microphone transducer may be configured to generate an analog input signal indicative of audio sounds incident upon the microphone transducer. The digital processing system may be configured to convert the analog input signal into a first digital signal having three or more quantization levels, and in the digital domain, process the first digital signal to convert the first digital signal into a second digital signal having two quantization levels.

10-09-2014

20140301572

SYSTEMS AND METHODS FOR COMPRESSING A DIGITAL SIGNAL IN A DIGITAL MICROPHONE SYSTEM - In accordance with embodiments of the present disclosure, a digital microphone system may include a microphone transducer and a digital processing system. The microphone transducer may be configured to generate an analog input signal indicative of audio sounds incident upon the microphone transducer. The digital processing system may be configured to convert the analog input signal into a first digital signal having a plurality (e.g., more than 3) of quantization levels, and in the digital domain, process the first digital signal to compress the first digital signal into a second digital signal having fewer quantization levels (e.g., +1, 0, −1) than that of the first digital signal.

10-09-2014

20140333205

STABILIZATION CIRCUIT FOR LOW-VOLTAGE LIGHTING - An electronic transformer stabilization circuit includes a detection circuit and a reactive load. The detection circuit may be configured to receive a transformer output or a transformer signal derived from the transformer output. The detection circuit may determine whether the transformer that generated the transformer output is an electronic transformer. The determination may be made based on the presence of absence of high frequency components in the transformer output. Responsive to determining that an electronic transformer generated the transformer output, the stabilization circuit may operate a switch to connect the reactive load across an output of the transformer. The reactive load may include an inductor and may be configured to draw a stabilization current from the transformer. The stabilization current may ensure that the total current drawn from the transformer exceeds an oscillation current required to maintain reliable operation of the electronic transformer.

11-13-2014

20140339995

SINGLE PIN CONTROL OF BIPOLAR JUNCTION TRANSISTOR (BJT)-BASED POWER STAGE - A power stage for light emitting diode (LED)-based light bulbs may include a bipolar junction transistor (BJT). The base of BJT switch may be biased externally and the operation of the BJT may be through a single pin to the emitter of the BJT. A controller integrated circuit (IC) may control the power stage through the main BJT's emitter pin in an emitter-controlled BJT-based power stage. The emitter-controlled BJT-based power stage may replace the conventional buck-boost power stage topology. For example, the controller may activate and deactivate a switch coupling the BJT's emitter to ground. A power supply for the controller IC may be charged from a reverse recovery of charge from the BJT, and the reverse recovery controlled by the controller IC.

11-20-2014

20140339999

CHARGE PUMP-BASED DRIVE CIRCUITRY FOR BIPOLAR JUNCTION TRANSISTOR (BJT)-BASED POWER SUPPLY - A bipolar junction transistor (BJT) may be used to generate a supply voltage for operating a controller, such as a lighting controller for a LED-based light bulb. A base of the BJT may receive current generated from the supply voltage to control operation of the BJT. Although the base of the BJT would be at a lower voltage than the emitter, a base drive circuit may be coupled between the emitter and the base of the BJT to increase the voltage. As one example, the base drive circuit may be a charge pump. In another example, the BJT may function as its own charge pump. In yet another example, a positive and a negative base current of the BJT may be independently controlled to regulate an output supply voltage V

11-20-2014

20150028764

TWO TERMINAL DRIVE OF BIPOLAR JUNCTION TRANSISTOR (BJT) FOR SWITCH-MODE OPERATION OF A LIGHT EMITTING DIODE (LED)-BASED BULB - A bipolar junction transistor (BJT) may be used in a power stage DC-to-DC converter, such as for LED-based light bulbs. The BJT may be switched on and off from a controller coupled to two terminals of the BJT. Through the two terminals, the control IC may dynamically adjust a reverse recovery time period of the BJT. The reverse recovery time period may be adjusted by changing an amount of base charge that accumulates on the BJT. Additional, the reverse recovery may be controlled through the use of a reverse base current source applied to the BJT after beginning switching off the BJT.

01-29-2015

20150028768

COMPENSATING FOR A REVERSE RECOVERY TIME PERIOD OF A BIPOLAR JUNCTION TRANSISTOR (BJT) IN SWITCH-MODE OPERATION OF A LIGHT-EMITTING DIODE (LED)-BASED BULB - A turn-off transition time period, also referred to as a reverse recovery time period, may be compensated for by a controller of a power stage including a bipolar junction transistor (BJT). The reverse recovery time period may be measured in one switching cycle and a subsequent switching cycle may include compensations based on the measured reverse recovery time period. That is the switching on and off of the BJT may be compensated to obtain a desired average output current to a load. When the reverse recovery time period is known, an error in the peak current obtained due to the reverse recovery time period may be calculated. The calculated error may be used to offset the target peak current for controlling the switching of the BJT to begin a turn-off transition of the BJT earlier in a switching cycle and thus reduce error in peak current at the BJT.

01-29-2015

20150054418

Multi-Mode Dimmer Interfacing Including Attach State Control - A system and method includes a controller that is configured to coordinate (i) a low impedance path for a dimmer current, (ii) attaching a dimmer to a power converter system at the leading edge of a phase-cut, rectified input voltage, (iii), control of switch mode power conversion, and (iv) an inactive state to, for example, reduce the dimmer current while allowing a dimmer to function normally from cycle to cycle of an alternating current (AC) supply voltage. In at least one embodiment, the dimmer functions normally when the dimmer conducts at a correct phase angle indicated by a dimmer input setting and avoids prematurely resetting while conducting. In at least one embodiment, by coordinating functions (i), (ii), (iii), and (iv) the controller controls a power converter system that is compatible with a triac-based dimmer.

02-26-2015

20150084535

DUTY FACTOR PROBING OF A TRIAC-BASED DIMMER - A line-frequency determining circuit for coupling to the output of a thyristor-switched dimmer that determines a line-frequency of an AC power source that supplies an input to the thyristor-controlled dimmer permits accurate control of periodic probing of the dimmer output. The probing is performed to predict zero-cross times of the AC power source that, in turn, are used to determine a dimming control value of the thyristor-switched dimmer. A minimum conductance is applied across the output of the dimmer during the probing intervals that begin at the turn-on time of the dimmer and last until enough information has been gathered to correctly predict a next zero crossing of the AC line voltage that supplies the input of the dimmer. The probing can be performed at intervals of an odd number of half-cycles of the AC line frequency so that internal dimmer timer operation is not affected by DC offset.